Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Lasse R. Braathen is active.

Publication


Featured researches published by Lasse R. Braathen.


Allergy | 2004

The prevalence of positive reactions in the atopy patch test with aeroallergens and food allergens in subjects with atopic eczema: a European multicenter study

Ulf Darsow; J. Laifaoui; K. Kerschenlohr; Andreas Wollenberg; Bernhard Przybilla; B. Wüthrich; S. Borelli; Francesca Giusti; Stefania Seidenari; K. Drzimalla; Dagmar Simon; R. Disch; A. C. A. Devillers; Arnold P. Oranje; L. De Raeve; J.‐P. Hachem; Chantal Dangoisse; A. Blondeel; Micheline Song; K. Breuer; A. Wulf; Thomas Werfel; S. Roul; A. Taïeb; S. Bolhaar; C. Bruijnzeel‐Koomen; M. Brönnimann; Lasse R. Braathen; A. Didierlaurent; C. André

Background:  The atopy patch test (APT) was proposed to evaluate IgE‐mediated sensitizations in patients with atopic eczema (AE).


Allergy | 2004

Eosinophils and atopic dermatitis.

D. Simon; Lasse R. Braathen; Hans-Uwe Simon

In spite of the progress regarding the description of immunological phenomena associated with atopic dermatitis (AD), the pathogenesis of this disease still remains unclear. The presence of eosinophils in the inflammatory infiltrate of AD has long been established. Eosinophil numbers as well as eosinophil granule protein levels in peripheral blood are elevated in most AD patients and appear to correlate with disease activity. Moreover, eosinophil granule proteins, which possess cytotoxic activity, are deposited in the skin lesions. These observations indicate a role of eosinophils in the pathogenesis of AD. Furthermore, AD is associated with increased production of T helper 2 cytokines including interleukin (IL)‐5, which specifically acts on eosinophils, resulting in accelerated eosinophilopoiesis, chemotaxis, cell activation, and delayed apoptosis. Therefore, IL‐5 is an interesting target for experimental therapy in this inflammatory disorder of the skin. Such studies might result in new insights into the pathogenetic role of eosinophils in AD.


American Journal of Pathology | 2002

Acute Generalized Exanthematous Pustulosis: Role of Cytotoxic T Cells in Pustule Formation

Simone Schmid; Petra Kuechler; Markus Britschgi; Urs C. Steiner; Nikhil Yawalkar; Alain Limat; Kurt Baltensperger; Lasse R. Braathen; Werner J. Pichler

Extensive formation of nonfollicular sterile pustules on erythematous background combined with fever and peripheral blood leukocytosis are the characteristics of acute generalized exanthematous pustulosis. This uncommon eruption most often is an allergic reaction because of drugs such as aminopenicillins and sulfonamides inter alia. We recently demonstrated the important role of drug-specific T cells in the pathogenesis of this disease, showing that they produce high amounts of the neutrophil-attracting chemokine interleukin-8 and therefore stand out as a special subgroup of T cells, differing from the usual Th1 and Th2 subsets. In this study we use immunohistochemistry as well as cytotoxicity assays (4- and 18-hour assays) and fluorescence-activated cell-sorting analysis of drug-specific circulating T cells and of cells eluted from the skin of five patients with acute generalized exanthematous pustulosis, to analyze whether cytotoxic T-cell functions are important in the pathogenesis of this disease, in particular for the formation of vesicles. The data reveal that drug-specific CD4(+) as well as CD8(+) T cells both are activated and cytotoxic; perforin/granzyme B and to a variable degree the Fas/FasL-killing mechanism is involved in tissue destruction. These features allow the formation of vesicles. Additional secretion of interleukin-8 by T cells and keratinocytes attracts neutrophils that fill the vesicles and transform them into pustules.


British Journal of Dermatology | 2001

Perforin and granzyme B may contribute to skin inflammation in atopic dermatitis and psoriasis

Nikhil Yawalkar; Simone Schmid; Lasse R. Braathen; Werner J. Pichler

Background Infiltration of the skin by pathogenic T cells is regarded as a key factor in the development of inflammatory skin diseases such as atopic dermatitis (AD) and psoriasis.


Allergy | 2006

Eosinophilic esophagitis in adults – no clinical relevance of wheat and rye sensitizations

Dagmar Simon; Alex Straumann; A. Wenk; Hans-Peter Spichtin; Hans-Uwe Simon; Lasse R. Braathen

Background:  Eosinophilic esophagitis (EE) is often associated with concomitant atopic diseases. In children with EE in whom food allergens have been identified as causative factors, elemental and elimination diets result in an improvement or resolution of symptoms. Most adult EE patients are sensitized to aeroallergens, which cross‐react with plant‐derived food allergens, most commonly to grass pollen and cereals.


International Wound Journal | 2006

Topical application of the tumour necrosis factor-alpha antibody infliximab improves healing of chronic wounds

Markus Streit; Zsuzsanna Beleznay; Lasse R. Braathen

The role of tumour necrosis factor‐alpha (TNF‐α) in wound healing is not clear. Elevated levels of TNF‐α have been observed in fluids from chronic wounds and have been shown to decrease over time during the healing process. Therapeutic antibodies such as infliximab can inhibit TNF‐α activity. In this case series, we applied infliximab topically to eight patients with chronic ulcers of more than 4‐month durations. The ulcers had multifactorial aetiology, with chronic venous insufficiency being the most prominent factor. All the ulcers had failed to respond to any previous conventional treatment. Infliximab was applied repeatedly to ulcers either as a 10 mg/ml solution and covered with an adhesive sheet or as a gel formulation (0·45, 1, or 4·5 mg/g) under a hydrofiber dressing/adhesive sheet. Improvement was assessed by measuring the percentage of change in the ulcer surface area. Seven of the eight patients (12 of 14 ulcers) responded to treatment with infliximab. After 4 weeks of treatment, surface area was reduced by more than 50% in 6 of the 14 treated ulcers. Within 8 weeks, five ulcers completely healed, while another four were reduced by more than 75% in size. Chronic, therapy‐resistant leg ulcers responded well to repeated topical administration of a solution or a gel containing the TNF‐α antibody, infliximab. Randomised controlled studies should be conducted to further evaluate the effect of topical infliximab on chronic wound healing.


Acta Dermato-venereologica | 2005

Photodynamic Therapy for Non-melanoma Skin Cancer

Rolf-Markus Szeimies; C.A. Morton; Alexis Sidoroff; Lasse R. Braathen

Photodynamic therapy is a treatment modality that has been shown to be effective mainly for the dermato-oncologic conditions: actinic keratosis, Bowens disease, in situ squamous cell carcinoma and basal cell carcinoma. Recent work has focused on the development and evaluation of topical photosensitizers like the haem precursor 5-aminolevulinic acid or its methyl ester, both inducing photosensitizing porphyrins. These drugs do not induce strong generalized cutaneous photosensitization, unlike the systemically applied porphyrins or their derivatives. For dermatological purposes incoherent lamps or light-emitting diode arrays can be used for light activation. Cure rates reported for very superficial lesions (tumour thickness <2-3 mm) are comparable to those achieved by other therapeutic modalities. Photodynamic therapy is a minimally invasive therapy associated with excellent cosmetic results. For actinic keratosis and basal cell carcinoma, methyl aminolevulinate-photodynamic therapy is already approved in Europe, Australia and New Zealand, and is now also approved for actinic keratosis in the US.


British Journal of Dermatology | 1992

Increased levels of inflammatory cytokines in human skin lymph derived from sodium lauryl sulphate-induced contact dermatitis

Thomas Hunziker; Ch. U. Brand; Alexander Kapp; E.R. Waelti; Lasse R. Braathen

Summary A superficial peripheral lymph vessel draining the skin of the upper and medial part of the foot was cannulated on the lower leg of six healthy human volunteers. After 2 days an irritant contact dermatitis was induced by application of 10% sodium lauryl sulphate to the area of skin drained by the lymph vessel. Three days later the spontaneously regressing skin reaction was treated with clobetasol propionate. Lymph was collected twice daily for 7 days, and the levels of various cytokines (IL‐1α, IL‐1β, IL‐2 and soluble IL‐2 receptors. IL‐6, IL‐8, TNF‐α, GM‐CSF) were determined by ELISA technique. In the majority of the volunteers all cytokines examined were detected in several lymph samples, with the exception of IL‐lα and IL‐8. In parallel with the clinical symptoms of the contact dermatitis the levels of IL‐6 and TNF‐α increased 8–l0‐fold, whereas for IL‐1β, IL‐2, IL‐2 receptors, and GM‐CSF there was a delayed, 2–3‐fold increase. These results suggest that cytokines, in particular IL‐6 and TNF‐α, may actively participate in the immunological reactions in the skin and in the regional lymph nodes during contact dermatitis.


Dermatology | 2008

Alopecia Areata Universalis Elicited during Treatment with Adalimumab

Nedzmidin Pelivani; Akmal S. Hassan; Lasse R. Braathen; Robert E. Hunger; Nikhil Yawalkar

Adalimumab is a fully humanized recombinant anti-tumour-necrosis-factor (TNF-α) monoclonal antibody which has been approved for rheumatoid arthritis, active ankylosing spondylitis, psoriatic arthritis and Crohn’s disease. We report a case of alopecia areata (AA) universalis occurring 6 months after administration of adalimumab monotherapy in a patient with a long-standing history of psoriatic arthritis and psoriasis. The diagnosis was confirmed by a scalp biopsy which showed a peribulbar infiltrate of both CD4+ and CD8+ T cells, CD1a+ dendritic cells as well as CD68+ and CD163+ macrophages. In addition, immunofluorescence staining for TNF-α was found in the mononuclear cell infiltrate. This case suggests a complex role of TNF-α in the induction of AA.


Archives of Dermatological Research | 2005

Mast cell chymase is increased in chronic atopic dermatitis but not in psoriasis

Karin Badertscher; Marcel Brönnimann; Stephan Karlen; Lasse R. Braathen; Nikhil Yawalkar

Mast cell chymase is a chymotrypsin-like serine proteinase primarily stored in secretory mast cell granules. Mast cell chymase has various effects on angiotensin, metalloproteases, lipoproteins, procollagen, neuropeptides and cytokines. Recent studies have demonstrated that chymase inhibitors inhibit skin inflammation. In this study we sought to determine the role of mast cell chymase in atopic dermatitis (AD) in comparison with its role in psoriasis and normal skin. Skin biopsy specimens were obtained from non-lesional and lesional skin of patients with chronic AD and psoriasis and from normal skin of non-atopic and non-psoriatic controls. The number of mast cells containing chymase was determined by immunohistochemistry using a chymase-specific monoclonal antibody. A significantly (P<0.05) enhanced number of chymase-positive cells was found in lesional AD skin as compared to normal skin as well as to lesional and non-lesional skin of patients with psoriasis. A significant (P<0.05) increase in the number of chymase-positive cells was also found in non-lesional AD skin in comparison to psoriasis. An enhanced, albeit not statistically significant difference was noted in non-lesional AD skin as compared to normal skin. In conclusion, these results suggest that mast cell chymase may play an integral part in eliciting and maintaining cutaneous inflammation in AD but not in psoriasis. The increased proteinase activity of mast cell chymase may also be involved in promoting a skin barrier defect in AD, which subsequently enhances the skin’s permeability to allergens and microbes and thereby aggravates the eczema.

Collaboration


Dive into the Lasse R. Braathen's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge